The Story of DNA
--- History of Molecular Biology
“History Teaches Everything, Including the Future.”--- Alphonse de Lamartine
Genetics
Biochemistry
Cell biology
Microbiology
Virology
…
1929 – the chemical components of DNA 1940 – the relationship between genes and proteins 1944 – Genes are made up of DNA
1953 – the double helical structure of the DNA molecule (Watson and Crick) 1957 – the “Central Dogma” and the “sequence hypothesis” (Crick)
1958 – the mechanism of DNA replication 1961 – the hypothesis of the messenger RNA (mRNA) 1961 to 1965 – the genetic code was deciphered ……
1970s to 80s – DNA cloning, sequencing and genetic engineering 1990s to 2000s – genome sequencing and functional study of genes
Overview of the History of Molecular Biology
1930 1940 1950 1960 1970 1980 1990 2000
Genes and DNA
DNA - RNA - protein
DNA cloning and genetic
engineering Genome eraDiscovery of
DNA
Overview of the History of Molecular Biology
• The discovery of DNA- Hofmeister (1848): discovery of chromosome
s- Miescher (1868): “nuclein” = DNA + protein
• Chromosome theory of inheritance- Mendel (1865): Laws of inheritance- Morgan (1910): Genes are on chromosomes
• Who carries genetic material, DNA or proteins?
The search of genetic material
1930 1940 1950 1960 1970 1980 1990 2000
Genes and DNA
DNA - RNA - proteinDNA cloning and
genetic engineering Genome eraDiscovery of
DNA
How did people know that DNA carries genetic information?
Avery, Macleod and McCarty’s experiment (1943)
http://www.dnaftb.org/dnaftb/17/animation/animation.html
1930 1940 1950 1960 1970 1980 1990 2000
Genes and DNA
DNA - RNA - proteinDNA cloning and
genetic engineering Genome eraDiscovery of
DNA
• A) What was the original observation that Avery made in test tubes?
• B) List two hypotheses based on the observation (doesn’t matter if they are right or wrong).
• C) What predictions would you make based on each of the hypotheses?
Avery’s Experiment on Pneumococcus:
How did people know that DNA carries genetic information?
Avery, Macleod and McCarty’s experiment (1943)
http://www.dnaftb.org/dnaftb/17/animation/animation.html
1930 1940 1950 1960 1970 1980 1990 2000
Genes and DNA
DNA - RNA - proteinDNA cloning and
genetic engineering Genome eraDiscovery of
DNA
The Double Helix
Watson Crick Wilkin Franklin
Crick and Watson: theoretical model
Wilkins and Franklin: X-ray diffraction
First accurate model of DNA's molecular structure (1953)
Nobel Prize, 1962
"Why You Are You. Nearer Secret of Life." --The News Chronicle of London
1930 1940 1950 1960 1970 1980 1990 2000
Genes and DNA
DNA - RNA - proteinDNA cloning and
genetic engineering Genome eraDiscovery of
DNA
Rosalind Franklin: The Dark Lady of DNA
Rosalind Franklin (1920-1958)
A British Biophysicist
Specialized in X-ray crystallography
King’s College, London (1951-1953):
- Worked with Maurice Wilkin and Raymond Gosling
Form A and B of DNA
Photograph 51
”The Eighth Day of Creation: Makers of the Revolution in Biology“ by Horace Freeland Judson
1957 – the “Central Dogma” (Crick)
1958 – the mechanism of DNA replication
1961 – the hypothesis of the messenger RNA
1961 to 1965 – the genetic code was deciphered
From DNA to Proteins
Howard Temin (Nobel Prize 1975)
Reverse transcriptase
1930 1940 1950 1960 1970 1980 1990 2000
Genes and DNA
DNA - RNA - proteinDNA cloning and
genetic engineering Genome eraDiscovery of
DNA
The Golden Age of Molecular Biology
1969: First gene in bacterial DNA isolated 1970: First synthetic (artificial) gene
1973: First successful DNA cloning experiment
1977: DNA is sequenced
1978: The first human gene is cloned – insulin 1982: Genetically-engineered insulin is approved for use
1985: PCR (Polymerase Chain Reaction) is invented
Har Gobind Khorana(Nobel Prize 1968)
1930 1940 1950 1960 1970 1980 1990 2000
Genes and DNA
DNA - RNA - proteinDNA cloning and
genetic engineering Genome eraDiscovery of
DNA
The Golden Age of Molecular Biology
1996: First genome sequenced – S. cerevisae (yeast) 1997: Bacteria E. coli genome sequenced 1998: C. elegans (worm) sequenced 2000: Drosophila (fruit fly) sequenced 2002: Mouse sequenced
2001: First draft sequences of the human genome are released (Human Genome Project)
2003: Completion of the mapping of the genes in the human genome
Fred Blattner
1930 1940 1950 1960 1970 1980 1990 2000
Genes and DNA
DNA - RNA - proteinDNA cloning and
genetic engineering Genome eraDiscovery of
DNA
What can we do with DNA?
Genetic engineering - Use model organisms to study
genes and functions - Make transgenic organisms
Applications for human - Forensics, paternity testing - Genetic diagnosis and prevention of diseases (Ge
netic counseling) - Gene therapy …
DNA and The Revolution in Personalized Medicine
Your life depends on the secret of your DNA…
Personalized Medicine - Genetic screening for prevention (newborn
screening, carrier screening, maternal screening, Pre-implantation Genetic Diagnosis (PGD))
- Risk prediction - The right drug at the right dose for the rig
ht person
Fields Related to Modern Molecular biology
Bioinformatics
Biophysics and Structural Biology
Population and evolutionary biology
Molecular genetics
Genomics
Cell Biology
Developmental Biology
Next class:
Case Study: The Human Genome Project and Designer Baby
Discussion of Molecular biology research groups on campus – What
do they do and why?